I don't read Hebrew but what I think I see based on mobi generated at gutenberg.org is that kfire has the glyphs but not the rtl support -- or else pg is doing something wrong in their gen. One might hope this might change come kf8 tool support. See freekindlebooks / Unicode KindleAllCodes.mobi to see what glyph points kfire supports.

I don't read Hebrew but what I think I see based on mobi generated at gutenberg.org is that kfire has the glyphs but not the rtl support -- or else pg is doing something wrong in their gen. One might hope this might change come kf8 tool support. See freekindlebooks / Unicode KindleAllCodes.mobi to see what glyph points kfire supports.

I must admit I didn't fully understood all you wrote...
I undertand that the kindle reading application itself doesn't support RTL but the Kindle Fire is an Android device and therefore any other reading application that supports RTL should work on it as well. What did I miss?

I must admit I didn't fully understood all you wrote...
I understand that the kindle reading application itself doesn't support RTL but the Kindle Fire is an Android device and therefore any other reading application that supports RTL should work on it as well. What did I miss?

Sorry, KFire is the first "Kindle" which can also be "Not a Kindle." I consider Silk, Android apps etc on KFire to be "Not a Kindle." IE "Kindle" can also be considered that ebook rendering software subset of KFire which takes kf8 or mobi and renders it onto the KFire screen.

Does KFire as a "Kindle" support Hebrew?

Apparently not at this time, although that answer may well change when the tools that support the new KF8 format come out.

Does the KFire Silk browser support Hebrew? IE Does "Silk" support Hebrew?

Apparently yes (Again, I do not actually read Hebrew, but) looking at the Hebrew examples on gutenberg.org using Silk I see Hebrew glyphs and those glyphs appears to be showing correctly in a RTL rendering matching the rendering on major well-known desktop HTML browsers running on an OS with well-known long time support for world languages and BIDI.

When one runs an Android app such as Aldiko on KFire, does "Aldiko" support Hebrew?

Maybe, kind-of. I download "Hunger" in epub from gutenberg.org using the Silk browser. Using well-documented tricks I use the Quickoffice file browser to move that epub from /Download to /eBooks/import -- which is where Aldiko looks for new books. I open Aldiko and choose the "Import" option. It finds the book, I open the book. Aldiko initially appears to support the book in *entirely* RTL mode, including swiping from RTL instead of LTR as-if one were reading a western-language LTR book from back-cover to front. But, after about one page of this then RTL swiping doesn't work, and I try LTR swiping and that does work, but I don't read Hebrew so I can't figure out for you whether or not it is a reasonable task in practice for someone who does read Hebrew to figure out whether these RTL vs LTR swiping issues are a big issue or a little issue, whether there are in fact contiguous page coverage there or not, or if some of the pages are somehow missing.

In summary: Get someone who owns a KFire, and who reads Hebrew, and who cares passionately about the KFire, and Hebrew, and EBook reader technology to answer this question definitively for you. Or perhaps saying the same thing: If you care passionately about this issue, and KFire, and Hebrew, and EBook reader technology, invest the time and money in KFire yourself and figure out what it takes to make KFire/Hebrew work together happily. Be a hero to the Hebrew-reader community. If this sounds unduly crabby, consider that I personally bought one of the very first Kindles and personally help forced open much of the "free books on Kindle" issue in the first place -- including personally providing literally millions of free books to Kindle owners. I also have been for a long time pushing on Amazon to include the Hebrew and Arabic glyphs on Kindle -- since their lone absence among the major languages offered glyph support on the Kindle looked very very strange (but potentially justifiable given that Kindles traditionally have not had RTL support)

Does KFire as a "Kindle" support Hebrew?
...
Love Hebrew? Love Arabic? Love Kindle? -- Make It Happen Yourself!

Thanks a lot for this detailed explanation and effort.

Personally, I'm not trying to find workarounds or complicated tricks to make the Kindle Fire read RTL languages. My question is simple: "Does it read Hebrew now using any of the reading Android apps available today?"
I opened this thread hoping that one of the Kindle Fire owners will spend a few minutes and check this issue. As soon as I'll get my hands on one I'll check it myself and post the results here.